In the fall of 1937, she traveled to the United States as a guest lecturer at Barnett College, where she was offered a post teaching the seminar course "Origins of the Incas 201"—a position previously promised to Indiana Jones. After receiving El Dedo de Oro from her brother Felipe, she and Professor Jones traveled to Buenos Aires to track down Felipe, who had disappeared. After numerous attacks and dead ends, the pair discovered a map to the location of Chimu Taya Arms of Cuzco, which they believed Felipe had also discovered. Traveling to Lake Titicaca, they were captured by Neo-Incas, only to discover that Felipe was leading them—and planned to use the mystical treasure to create a new Incan empire. Felipe revealed that Francisca had planned some of the attacks on Jones, as part of an attempt for vengeance for perceived wrongs against their father; Jones asserted that he knew of her treachery all along.

Felipe's plans demanded that Francisca be the consort of her own brother, and she was drugged and brought to Pachacuti's tomb. When the tomb began to collapse, she tried to save her brother, but he pushed her aside from a falling throne and perished. As water filled the tomb, she saved Indiana Jones' life. Back in Lima, with her attempts at vengeance behind her, Francisca and Indy pursued romance.